Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| [the role of the structural components of bacterial lipopolysaccharide in its inductive immunosuppressive activity]. | the inductive immunosuppressive activity of lipopolysaccharides (lps) and structural parts (o-chains,cor,lipid a) obtained from bacteria of the genus shigella and escherichia coli was studied. lps preparations were extracted by phenol-water method. its structural components were obtained by the acetic acid hydrolysis and gel filtration. it has been shown that all these preparations did not change the level of delayed type hypersensitivity (dth) to test-antigen in mice in the case of intraperiton ... | 1999 | 10707531 |
| serogroup prevalence of shigellae in bombay. | prevalence of shigellae serotypes in bombay was studied from june 1988 to may 1991. a total of 2758 faecal specimens were collected from paediatric patients (< 12 yrs) with acute gastroenteritis. a total of 90 shigella were isolated giving the isolation rate of 3.2%. shigella flexneri was the predominant serogroup (73.3%) followed by shigella dysenteriae (16.6%). all the isolates were sensitive to nalidixic acid. eighty percent of the shigellae were multidrug resistant. present data were compare ... | 1995 | 10707731 |
| the development of a facs-based strategy for the isolation of shigella flexneri mutants that are deficient in intercellular spread. | in the disease course of bacillary dysentery, pathogenic shigella flexneri invade colonic epithelial cells and spread both within and between host cells. the ability to spread intercellularly allows the organism to infect an entire epithelial layer without significant contact with the extracellular milieu. using fluorescence activated cell sorter (facs)-based technology, we developed a rapid and powerful selection strategy for the isolation of s. flexneri mutants that are unable to spread from c ... | 2000 | 10712681 |
| deltaguaba attenuated shigella flexneri 2a strain cvd 1204 as a shigella vaccine and as a live mucosal delivery system for fragment c of tetanus toxin. | the deltaguaba shigella flexneri 2a vaccine candidate, cvd 1204, was evaluated as a delivery system for the non-toxic c-terminal of tetanus toxin (fragment c), either as a polypeptide expressed in the bacteria or as a dna vaccine. cvd 1204 was transformed with plasmid ptetnir15 which encodes the fragment c gene (tetc) under the control of the inducible prokaryotic nir15 promoter or a dna vaccine plasmid pcdna3tetc which encodes tetc under the eukaryotic hcmv promoter. guinea pigs immunised intra ... | 2000 | 10717338 |
| survival of some species of salmonella and shigella in mukumbi, a traditional zimbabwean wine. | mukumbi is a traditional zimbabwean wine prepared from a fruit called mapfura by the shona people of zimbabwe and amaganu by the ndebele. the majority of people in africa call the tree marula (sclerocarya birrea subspecies caffra). the survival of salmonella group b, salmonella enteritidis, shigella sonnei and shigella flexneri in unfermented and fermented mapfura (marula) juice (mukumbi) was investigated. it was found that within 30 min of inoculation, there were no longer any viable pathogens ... | 1999 | 10719586 |
| construction of an efficient expression system for agrobacterium tumefaciens based on the coliphage t5 promoter. | a versatile expression vector utilizing a promoter of coliphage t5, p(n25) (gentz and bujard, 1985. j. bacteriol. 164, 70-77) and a derivative of the incw broad-host-range plasmid pjb20 (beaupré et al., 1997. j. bacteriol. 179, 78-89) has been developed. this vector successfully expresses virulence proteins of agrobacterium tumefaciens encoded by virg and a mutant allele of vira, vira (delta1-284, g665d) in escherichia coli as well as in a. tumefaciens. the signal transduction proteins vira (del ... | 2000 | 10721702 |
| emergence of antimicrobial-resistant shigellosis in oregon. | ampicillin and trimethoprim-sulfamethoxazole (tmp-smz) are currently considered acceptable empirical therapy for shigellosis in developed countries. however, there are few recently reported studies on antimicrobial resistance among shigellae isolated in the united states. we examined the epidemiology of shigellosis and the antimicrobial susceptibility of shigella species isolated in oregon from july 1995 through june 1998. of 430 isolates, 410 were identified to the species level: shigella sonne ... | 2000 | 10722437 |
| clostridium difficile recombinant toxin a repeating units as a carrier protein for conjugate vaccines: studies of pneumococcal type 14, escherichia coli k1, and shigella flexneri type 2a polysaccharides in mice. | unlike the native protein, a nontoxic peptide (repeating unit of the native toxin designated raru) from clostridium difficile toxin a (cdta) afforded an antigen that could be bound covalently to the surface polysaccharides of pneumococcus type 14, shigella flexneri type 2a, and escherichia coli k1. the yields of these polysaccharide-protein conjugates were significantly increased by prior treatment of raru with succinic anhydride. conjugates, prepared with raru or succinylated (rarusucc), were a ... | 2000 | 10722615 |
| shigella actin-based motility in the presence of truncated vinculin. | mounting evidence supports the role of truncated vinculin in the intracellular actin-based motility of shigella flexneri. vinculin's role was recently questioned by goldberg [1997: cell motil cytoskeleton 37:44-53] who observed shigella motility in mouse embryonal carcinoma 5.51 cells, a genetically modified cell line that reputedly lacked vinculin. that challenge implicitly relied on the assumption that 5.51 cells had no detectable vinculin polypeptide and lacked full-length vinculin mrna. desp ... | 2000 | 10744860 |
| antimicrobial resistance trends in shigella serogroups isolated in israel, 1990-1995. | from a total of 31319 shigella strains isolated in israel between 1990 and 1996, 17574 were sent to the national shigella reference center for typing. of these, 15287 were identified as shigella sonnei, 1833 as shigella flexneri, 327 as shigella boydii and 127 as shigella dysenteriae. in all, 4395 strains were tested for sensitivity to ampicillin, trimethoprim-sulfamethoxazole, tetracycline, chloramphenicol, nalidixic acid and ofloxacin. all strains tested were sensitive to ofloxacin, and only t ... | 2000 | 10746496 |
| antagonistic effect of lactobacillus acidophilus, saccharomyces boulardii and escherichia coli combinations against experimental infections with shigella flexneri and salmonella enteritidis subsp. typhimurium in gnotobiotic mice. | lactobacillus acidophilus, saccharomyces boulardii and escherichia coli are probiotic strains used individually to protect against enteropathogenic agents. in order to determine if a synergistic effect of the individual protective mechanisms ordinarily attributed to each of these biotherapeutic agents is possible, we orally administered lact. acidophilus h2b20, s. boulardii and e. coli emo (lse) to germfree mice. ten days after colonization of the digestive tract, groups of animals associated (e ... | 2000 | 10747216 |
| [antimicrobial resistance of shigella spp. in córdoba, argentina, during the period 1990-1997]. | this study analyzed the evolution of antimicrobial resistance in 771 isolates of shigella spp. obtained from a total of 9,195 feces cultures done between 1990 and 1997 in a children's hospital in córdoba, argentina. s. flexneri, which was responsible for 73% of the shigella infections, was the species with the greatest resistance. the frequency of s. flexneri resistance to the three antibiotics most used (ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol) increased from 10% in 1990 ... | 2000 | 10748662 |
| [erythromycin sensitivity of shigella flexneri and s. sonnei]. | 2000 | 10756447 | |
| the stability region of the large virulence plasmid of shigella flexneri encodes an efficient postsegregational killing system. | the large virulence plasmid pmysh6000 of shigella flexneri contains a determinant that is highly effective in stabilizing otherwise unstable plasmids in escherichia coli. expression of two small contiguous genes, mvpa and mvpt (formerly termed stborf1 and stborf2), was shown to be sufficient for stability. mutations in mvpt abolished plasmid stability, and plasmids expressing only mvpt killed the cells unless mvpa was supplied from a separate plasmid or from the host chromosome. when replication ... | 2000 | 10762240 |
| comparison of six dose-response models for use with food-borne pathogens. | food-related illness in the united states is estimated to affect over six million people per year and cost the economy several billion dollars. these illnesses and costs could be reduced if minimum infectious doses were established and used as the basis of regulations and monitoring. however, standard methodologies for dose-response assessment are not yet formulated for microbial risk assessment. the objective of this study was to compare dose-response models for food-borne pathogens and determi ... | 1999 | 10765449 |
| the siga gene which is borne on the she pathogenicity island of shigella flexneri 2a encodes an exported cytopathic protease involved in intestinal fluid accumulation. | in this study, the siga gene situated on the she pathogenicity island of shigella flexneri 2a was cloned and characterized. sequence analysis showed that siga encodes a 139.6-kda protein which belongs to the spate (serine protease autotransporters of enterobacteriaceae) subfamily of autotransporter proteins. the demonstration that siga is autonomously secreted from the cell to yield a 103-kda processed form and possesses a conserved c-terminal domain for export from the cell were consistent with ... | 2000 | 10768931 |
| the shda gene is restricted to serotypes of salmonella enterica subspecies i and contributes to efficient and prolonged fecal shedding. | little is known about factors which enable salmonella serotypes to circulate within populations of livestock and domestic fowl. we have identified a dna region which is present in salmonella serotypes commonly isolated from livestock and domestic fowl (s. enterica subspecies i) but absent from reptile-associated salmonella serotypes (s. bongori and s. enterica subspecies ii to vii). this dna region was cloned from salmonella serotype typhimurium and sequence analysis revealed the presence of a 6 ... | 2000 | 10768965 |
| the seasonal variation in the microbial agents implicated in the etiology of diarrheal diseases among children in lao people's democratic republic. | during 1994-1995, the etiological structure of children's diarrhea was monitored in outpatients at mahosot hospital, vientiane, lao pdr. of the 191 children studied, 42% had stool specimens positive for enteropathogens; 22% had rotavirus, 21.5% enteropathogenic e. coli, 4.7% shigella flexneri, 2.9% campylobacter jejuni, 2.1% shigella sonnei, and 0.5% each of giardia intestinalis and entamoeba histolytica. no vibrio cholerae and salmonella spp. was detected in this monitoring. in children under f ... | 1999 | 10774703 |
| complete nucleotide sequence of tn10. | the complete nucleotide sequence of tn10 has been determined. the dinucleotide signature and percent g+c of the sequence had no discontinuities, indicating that tn10 constitutes a homogeneous unit. the new sequence contained three new open reading frames corresponding to a glutamate permease, repressors of heavy metal resistance operons, and a hypothetical protein in bacillus subtilis. the glutamate permease was fully functional when expressed, but tn10 did not protect escherichia coli from the ... | 2000 | 10781570 |
| detection of pcr products of the ipah gene from shigella and enteroinvasive escherichia coli by enzyme linked immunosorbent assay. | pcr techniques applied to diarrheal stools reliably diagnose shigella and enteroinvasive escherichia coli (eiec) infections. identification of pcr products using agarose gel electrophoresis (age) and hybridization with dna probes has several shortcomings. automated methods of identifying pcr products that process larger numbers of specimens can facilitate epidemiologic studies and standardize results. in this study, we used elisa following pcr to detect ipah gene sequences of shigella and eiec f ... | 2000 | 10794934 |
| a high incidence of shigella-induced arthritis in a primate species: major histocompatibility complex class i molecules associated with resistance and susceptibility, and their relationship to hla-b27. | the human major histocompatibility complex (mhc) class i gene, hla-b27, is a strong risk factor for susceptibility to a group of disorders termed spondyloarthropathies. rodents that express hla-b27 develop spondyloarthropathies, implicating hla-b27 in the etiology of these disorders. to determine whether an hla-b27-like molecule was associated with spondyloarthropathies in nonhuman primates, we analyzed the mhc class i cdnas expressed in a cohort of rhesus macaques that developed reactive arthri ... | 2000 | 10803844 |
| shigella flexneri ipah(7.8) facilitates escape of virulent bacteria from the endocytic vacuoles of mouse and human macrophages. | the behavior of shigella flexneri ipah mutants was studied in human monocyte-derived macrophages (hmdm), in 1-day-old human monocytes, and in j774 mouse macrophage cell line. in hmdm, strain pwr700, an ipah(7.8) deletion mutant of s. flexneri 2a strain 2457t, behaved like the wild-type strain 2457t. this strain caused rapid host cell death by oncosis, and few bacterial cfu were recovered after incubation in the presence of gentamicin as previously described for 2457t-infected hmdm. however, anal ... | 2000 | 10816519 |
| interaction of shigella flexneri ipac with model membranes correlates with effects on cultured cells. | invasion of enterocytes by shigella flexneri requires the properly timed release of ipab and ipac at the host-pathogen interface; however, only ipac has been found to possess quantifiable activities in vitro. we demonstrate here that when added to cultured cells, purified ipac elicits cytoskeletal changes similar to those that occur during shigella invasion. this ipac effect may correlate with its ability to interact with model membranes at physiological ph and to promote entry by an ipac mutant ... | 2000 | 10816532 |
| curli loci of shigella spp. | an unstable chromosomal element encoding multiple antibiotic resistance in shigella flexneri serotype 2a was found to include sequences homologous to the csg genes encoding curli in escherichia coli and salmonella enterica serovar typhimurium. as curli have been implicated in the virulence of serovar typhimurium, we investigated the csg loci in all four species of shigella. dna sequencing and pcr analysis showed that the csg loci of a wide range of shigella strains, of diverse serotypes and diff ... | 2000 | 10816548 |
| matrix-assisted laser desorption/ionization time-of-flight mass spectrometric detection of bacterial biomarker proteins isolated from contaminated water, lettuce and cotton cloth. | matrix-assisted laser desorption/ionization time-of-flight (maldi-tof) mass spectra of bacterial proteins were obtained from water, lettuce and cloth samples contaminated with shigella flexneri, escherichia coli, and aeromonas hydrophila. spectra were obtained using proteins directly isolated from water (or water used for rinsing samples) without culturing the bacteria. for s. flexneri and e. coli, two marker ions for specific proteins associated with a virulence-related property (acid resistanc ... | 2000 | 10825256 |
| rho family gtpase cdc42 is essential for the actin-based motility of shigella in mammalian cells. | shigella, the causative agent of bacillary dysentery, is capable of directing its movement within host cells by exploiting actin dynamics. the virg protein expressed at one pole of the bacterium can recruit neural wiskott-aldrich syndrome protein (n-wasp), a downstream effector of cdc42. here, we show that cdc42 is required for the actin-based motility of shigella. microinjection of a dominant active mutant cdc42, but not rac1 or rhoa, into swiss 3t3 cells accelerated shigella motility. in add-b ... | 2000 | 10839806 |
| caspase-1 activation of il-1beta and il-18 are essential for shigella flexneri-induced inflammation. | caspases are intracellular proteases that mediate mammalian cell apoptosis. caspase-1 (casp-1) is a unique caspase because it activates the proinflammatory cytokines interleukin (il)-1beta and il-18. shigella flexneri, the etiological agent of bacillary dysentery, induces macrophage apoptosis, which requires casp-1 and results in the release of mature il-1beta and il-18. here we show that casp-1(-/-) mice infected with s. flexneri do not develop the acute inflammation characteristic of shigellos ... | 2000 | 10843390 |
| disease-dependent changes in t-cell populations in patients with shigellosis. | in shigellosis, bacterial infection is associated with an extensive inflammation of the rectal mucosa, resulting in bloody dysentery. the role of t-cell-mediated pro-inflammatory mechanisms has been implicated in this process, but the specific role of t-cell subsets is still not well understood. in this study we attempted to identify the changes in t-cell populations in patients with shigellosis during the disease course. the t-cell subset distribution was analyzed by immunohistochemistry in the ... | 2000 | 10843411 |
| [a case report: a small outbreak of flexner dysentery in a kindergarten]. | 1999 | 10852012 | |
| characterization of the genes encoding the shea haemolysin in escherichia coli o157:h7 and shigella flexneri 2a. | 2000 | 10865950 | |
| profilin is required for sustaining efficient intra- and intercellular spreading of shigella flexneri. | the ability of shigella to mediate actin-based motility within the host cell is a prominent pathogenic feature of bacillary dysentery. the ability is dependent on the interaction of virg with neural wiskott-aldrich syndrome protein (n-wasp), which in turn mediates recruitment of arp2/3 complex and several actin-related proteins. in the present study, we show that profilin i is essential to the rapid movement of shigella in epithelial cells, for which the capacity of profilin to interact with g-a ... | 2000 | 10867004 |
| inorganic polyphosphate: a molecule of many functions. | inorganic polyphosphate (poly p) is a chain of tens or many hundreds of phosphate (pi) residues linked by high-energy phosphoanhydride bonds. despite inorganic polyphosphate's ubiquity--found in every cell in nature and likely conserved from prebiotic times--this polymer has been given scant attention. among the reasons for this neglect of poly p have been the lack of sensitive, definitive, and facile analytical methods to assess its concentration in biological sources and the consequent lack of ... | 1999 | 10872445 |
| the pathogenesis of shigella flexneri infection: lessons from in vitro and in vivo studies. | shigella flexneri is a gram-negative facultatively intracellular pathogen responsible for bacillary dysentery in humans. more than one million deaths occur yearly due to infections with shigella spp. and the victims are mostly children of the developing world. the pathogenesis of shigella centres on the ability of this organism to invade the colonic epithelium where it induces severe mucosal inflammation. much information that we have gained concerning the pathogenesis of shigella has been deriv ... | 2000 | 10874731 |
| [shigellosis and other acute intestinal infections in the republic of tajikistan: the epidemiological patterns]. | acute enteric infections (aei), including shigellosis, are characterized by their extremely wide spread in tajikistan. their hyperendemicity is due to a high activity of the water route of transmission under the conditions of hot climate. the morbidity level of aei both in the republic as a whole and in its individual territories has been found to directly depend on the degree of the potential epidemiological danger of the water supply system, as well as on the quality of water used by the popul ... | 1999 | 10876848 |
| invasive shigella flexneri activates nf-kappa b through a lipopolysaccharide-dependent innate intracellular response and leads to il-8 expression in epithelial cells. | the pathogenesis of shigella flexneri infection centers on the ability of this organism to invade epithelial cells and initiate an intense inflammatory reaction. because nf-kappa b is an important transcriptional regulator of genes involved in inflammation, we investigated the role of this transcription factor during s. flexneri infection of epithelial cells. infection of hela cells with invasive s. flexneri induced nf-kappa b dna-binding activity; noninvasive s. flexneri strains did not lead to ... | 2000 | 10878365 |
| amino acid substitutions in a variant of imp-1 metallo-beta-lactamase. | in the course of surveying for the carbapenem-hydrolyzing metallo-beta-lactamase gene bla(imp) in pathogenic bacteria by the pcr method, we detected a gene encoding a variant metallo-beta-lactamase, designated imp-3, which differed from imp-1 by having low hydrolyzing activity for penicillins and carbapenems. pcr product direct sequencing of a 2.2-kb segment revealed that the gene bla(imp-3) was located on a cassette inserted within a class i integron in the pms390 plasmid. the 741-bp nucleotide ... | 2000 | 10898670 |
| beta-lactamases in shigella flexneri isolates from hong kong and shanghai and a novel oxa-1-like beta-lactamase, oxa-30. | ninety-one ampicillin-resistant shigella flexneri strains from hong kong and shanghai were studied for production of beta-lactamases. tem-1-like and oxa-1-like enzymes were identified in 21 and 79% of the strains, respectively, by isoelectric focusing (ief). no difference in the pattern of beta-lactamase production was found between strains from hong kong and shanghai. four ribotypes were detected. over 88% of oxa-producing strains had the same ribotype. all tem-1-like strains harbored a plasmid ... | 2000 | 10898672 |
| a macrophage invasion mechanism for mycobacteria implicating the extracellular domain of cd43. | we studied the role of cd43 (leukosialin/sialophorin), the negatively charged sialoglycoprotein of leukocytes, in the binding of mycobacteria to host cells. cd43-transfected hela cells bound mycobacterium avium, but not salmonella typhimurium or shigella flexneri. quantitative bacteriology showed that macrophages (m(phi)) from wild-type mice (cd43(+/+)) bound m. avium, mycobacterium bovis (bacillus calmette-guérin), and mycobacterium tuberculosis (strain h37rv), whereas m(phi) from cd43 knockout ... | 2000 | 10899905 |
| [diarrheal disease among caregivers at children's day-care centers. a retrospective and seroepidemiologic study]. | diarrheal disease tends to spread from infected children to their families. due to the increased risk of exposure, children's caregivers in day-care centers may have a higher incidence of diarrhea, particularly when caring for very young children. we therefore examined the incidence of diarrhea and antibodies to shigella among caregivers in day-care centers, according to age groups of children in their care (< 18, 18-34, and > 35 months) and in comparison with the general population. 2 studies w ... | 1999 | 10914170 |
| synthesis and antimicrobial activity of 4-carbethoxymethyl-2-[(alpha-haloacyl)amino] thiazoles and 5-nonsubstituted/substituted 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones. | 4-carbethoxymethyl-2-[(chloroacetyl/alpha-chloropropionyl/al pha- bromobutyryl/alpha-chloro-(alpha-phenylacetyl)amino]thiazoles (i-iv) were synthesized by reacting 4-carbethoxymethyl-2-aminothiazole with chloroacetyl chloride, alpha-chloropropionyl chloride, alpha-bromobutyryl bromide and alpha-chloro-alpha-phenylacetyl chloride, respectively. furthermore, i-iv were refluxed with ammonium thiocyanate to give 2-[(4-carbethoxymethylthiazol-2-yl)imino]-4-thiazolidinones (v-viii). v was refluxed wit ... | 2000 | 10918953 |
| supramolecular structure of the shigella type iii secretion machinery: the needle part is changeable in length and essential for delivery of effectors. | we investigated the supramolecular structure of the shigella: type iii secretion machinery including its major components. our results indicated that the machinery was composed of needle and basal parts with respective lengths of 45.4 +/- 3.3 and 31.6 +/- 0.3 nm, and contained mxid, mxig, mxij and mxih. spa47, encoding a putative f(1)-type atpase, was required for the secretion of effector proteins via the type iii system and was involved in the formation of the needle. the spa47 mutant produced ... | 2000 | 10921870 |
| attenuated shigella flexneri 2a vaccine strain cvd 1204 expressing colonization factor antigen i and mutant heat-labile enterotoxin of enterotoxigenic escherichia coli. | a multivalent live oral vaccine against both shigella spp. and enterotoxigenic escherichia coli (etec) is being developed based on the hypothesis that protection can be achieved if attenuated shigellae express etec fimbrial colonization factors and genetically detoxified heat-labile toxin from a human etec isolate (lth). two detoxified derivatives of lth, lthk63 and lthr72, were engineered by substitution-serine to lysine at residue 63, or lysine to arginine at residue 72. the genes encoding the ... | 2000 | 10948101 |
| diversion of cytoskeletal processes by shigella during invasion of epithelial cells. | shigella, the causative agent of bacillar dysentery, invades colonic epithelial cells and moves intracellularly to spread from cell to cell. the processes of shigella entry, determined by the ipa proteins, and of actin-based motility, dependent on the icsa/virg protein, represent different levels of bacterial manipulation of the cell cytoskeleton. | 2000 | 10955962 |
| characterization of the interaction of ipab and ipad, proteins required for entry of shigella flexneri into epithelial cells, with a lipid membrane. | entry of shigella flexneri into epithelial cells and lysis of the phagosome involve the ipab, ipac, and ipad proteins, which are secreted by type iii secretion machinery. we report here the purification of ipab and ipad and the characterization of their lipid-binding properties as a function of ph. the interaction of ipab with the membrane was quite independent of the ph whereas that of ipad took place only at low ph. to support the data obtained with the purified proteins, we designed a system ... | 2000 | 10971588 |
| galanin-1 receptor up-regulation mediates the excess colonic fluid production caused by infection with enteric pathogens. | galanin is widely distributed in enteric nerve terminals lining the gastrointestinal tract. we previously showed that pathogenic escherichia coli, but not normal commensal organisms, increase galanin-1 receptor expression by epithelial cells lining the colon (i.e., colonocytes). when present, galanin-1 receptor activation by ligand causes colonocyte cl- secretion. we herein demonstrate that disparate pathogens including salmonella typhimurium and shigella flexerii also increase colonocyte galani ... | 2000 | 10973327 |
| treatment of bacillary dysentery in vietnamese children: two doses of ofloxacin versus 5-days nalidixic acid. | nalidixic acid (na: 55 mg/kg daily for 5 days) is the recommended treatment for uncomplicated bacillary dysentery in areas where multidrug-resistant shigella are prevalent. an open randomized comparison of this na regimen with 2 doses of ofloxacin (total 15 mg/kg) was conducted in 1995/96 in 135 vietnamese children with fever and bloody diarrhoea. sixty-six children with a bacterial pathogen isolated were eligible for analysis. of the 63 shigella isolates, 39 (62%) were resistant to multiple ant ... | 2000 | 10975012 |
| myosin light chain kinase plays an essential role in s. flexneri dissemination. | shigella flexneri, the causitive agent of bacillary dysentery, has been shown to disseminate in colonic epithelial cells via protrusions that extend from infected cells and are endocytosed by adjacent cells. this phenomenon occurs in the region of the eukaryotic cell's adherens junctions and is inhibited by pharmacological reagents or host cell mutations that completely disrupt the junctional complex. in this study, inhibitors of the myosin light chain kinase (mlck) were shown to dramatically de ... | 2000 | 10984429 |
| tripeptidyl peptidase ii promotes maturation of caspase-1 in shigella flexneri-induced macrophage apoptosis. | the invasive enteropathogenic bacterium shigella flexneri activates apoptosis in macrophages. shigella-induced apoptosis requires caspase-1. we demonstrate here that tripeptidyl peptidase ii (tppii), a cytoplasmic, high-molecular-weight protease, participates in the apoptotic pathway triggered by shigella. the tppii inhibitor ala-ala-phe-chloromethylketone (aaf-cmk) and clasto-lactacystin beta-lactone (lactacystin), an inhibitor of both tppii and the proteasome, protected macrophages from shigel ... | 2000 | 10992446 |
| triphenyltin salicylate-antimicrobial effect and resistance--the pyrophosphatase connection. | the effect of triphenyltin salicylate (tps) was tested against six bacteria, escherichia coli, staphylococcus aureus, shigella flexneri, pseudomonas aeruginosa, klebsiella pneumoniae and salmonella typhi and five fungi, aspergillus flavus, aspergillus fumigatus, aspergillus niger, rhodotorula spp. and saccharomyces spp. sensitivity tests were determined with 5-500 microg/ml of tps. all organisms were sensitive to the compound except klebsiella pneumoniae, pseudomonas aeruginosa, rhodotorula spp. ... | 2000 | 10995071 |
| genetic analysis of escherichia coli k1 gastrointestinal colonization. | strains of escherichia coli expressing the k1 polysaccharide capsule colonize the large intestine of newborn infants, and are the leading cause of gram-negative septicaemia and meningitis in the neonatal period. we used signature-tagged mutagenesis (stm) to identify genes that e. coli k1 requires to colonize the gastrointestinal (gi) tract. a total of 2140 mtn5 mutants was screened for their capacity to colonize the gi tract of infant rats, and 16 colonization defective mutants were identified. ... | 2000 | 10998163 |
| improved template preparation for pcr-based assays for detection of food-borne bacterial pathogens. | shigella flexneri, salmonella enterica serotype typhimurium, and listeria monocytogenes were applied to fta filters, and the filters were used directly as templates to demonstrate their sensitivity and applicability in pcr-based detection assays. with pure cultures, the sensitivities of detection by fta filter-based pcr were 30 to 50 and 200 cfu for the gram-negative enterics and listeria, respectively. different numbers of s. flexneri cells were used in controlled contamination experiments with ... | 2000 | 11010913 |
| isolation and antibiotic susceptibility of salmonella, shigella, and campylobacter from acute enteric infections in egypt. | while campylobacter, salmonella, and shigella remain major contributors to acute enteric infections, few studies on these pathogens have been conducted in egypt. from january 1986 to december 1993, 869 salmonella, shigella and campylobacter strains were isolated from stool specimens from 6,278 patients, presenting to the abbassia fever hospital, cairo, egypt, with acute enteric infections. salmonella predominated, totalling 465 isolates, followed by shigella with 258 isolates, and campylobacter ... | 2000 | 11014768 |
| vibrio fischeri lipopolysaccharide induces developmental apoptosis, but not complete morphogenesis, of the euprymna scolopes symbiotic light organ. | during initiation of the association between the squid host euprymna scolopes and its bacterial partner vibrio fischeri, the bacteria induce dramatic morphogenesis of the host symbiotic organ, a portion of which involves the signaling of widespread apoptosis of the cells in a superficial ciliated epithelium on the colonized organ. in this study, we investigated the role in this process of lipopolysaccharide (lps), a bacterial cell-surface molecule implicated in the induction of animal cell apopt ... | 2000 | 11023684 |
| ipgd, a protein secreted by the type iii secretion machinery of shigella flexneri, is chaperoned by ipge and implicated in entry focus formation. | invasion of epithelial cells by shigella flexneri involves entry and intercellular dissemination. entry of bacteria into non-phagocytic cells requires the ipaa-d proteins that are secreted by the mxi-spa type iii secretion machinery. type iii secretion systems are found in several gram-negative pathogens and serve to inject bacterial effector proteins directly into the cytoplasm of host cells. in this study, we have analysed the ipgd protein of s. flexneri, the gene of which is located on the vi ... | 2000 | 11029686 |
| bifidobacterium strains from resident infant human gastrointestinal microflora exert antimicrobial activity. | the gastrointestinal microflora exerts a barrier effect against enteropathogens. the aim of this study was to examine if bifidobacteria, a major species of the human colonic microflora, participates in the barrier effect by developing antimicrobial activity against enterovirulent bacteria. | 2000 | 11034580 |
| key role for dsba in cell-to-cell spread of shigella flexneri, permitting secretion of ipa proteins into interepithelial protrusions. | dsba, a disulfide bond catalyst, is necessary for realization of the pathogenic potential of shigella flexneri. sh42, a mutant strain differing from wild-type m90ts solely because it expresses nonfunctional dsba33g (substitution for 33c at the active site), secreted less ipab and ipac than m90ts in response to various stimuli in vitro. a kinetic study demonstrated that sh42 responded more slowly to congo red than m90ts. by modulating relative concentrations of functional and nonfunctional dsba w ... | 2000 | 11035758 |
| zentralblatt für bakteriologie--100 years ago: the isolation of shigella flexneri. | 2000 | 11043976 | |
| the ternary transformation system: constitutive virg on a compatible plasmid dramatically increases agrobacterium-mediated plant transformation. | this paper describes a so-called ternary transformation system for plant cells. we demonstrate that agrobacterium tumefaciens strain lba4404 supplemented with a constitutive virg mutant gene (virgn54d) on a compatible plasmid is capable of very efficient t-dna transfer to a diverse range of plant species. for the plant species catharanthus roseus it is shown that increased t-dna transfer results in increased stable transformation frequencies. analysis of stably transformed c. roseus cell lines s ... | 2000 | 11052201 |
| shigella flexneri bacteremia in a middle-aged immunocompetent woman. | 2000 | 11055675 | |
| uptake pathways of clinical and healthy animal isolates of campylobacter jejuni into int-407 cells. | campylobacter jejuni isolates obtained from human and animal sources showed different invasion levels into human embryonic intestinal (int-407) cells. there was no significant relation between the degree of invasion and cytotoxins production. the depolymerization of both microfilaments by cytochalasin-d and microtubules by colchicine, demecolcine and nocodazole or stabilization of microtubules by paclitaxel reduced the invasiveness of c. jejuni, although microfilament depolymerization showed gre ... | 2000 | 11064267 |
| isolation and characterization of a shigella flexneri invasin complex subunit vaccine. | the invasiveness and virulence of shigella spp. are largely due to the expression of plasmid-encoded virulence factors, among which are the invasion plasmid antigens (ipa proteins). after infection, the host immune response is directed primarily against lipopolysaccharide (lps) and the virulence proteins (ipab, ipac, and ipad). recent observations have indicated that the ipa proteins (ipab, ipac, and possibly ipad) form a multiprotein complex capable of inducing the phagocytic event which intern ... | 2000 | 11083774 |
| studies of the small bowel surface by scanning electron microscopy in infants with persistent diarrhea. | we describe the ultrastructural abnormalities of the small bowel surface in 16 infants with persistent diarrhea. the age range of the patients was 2 to 10 months, mean 4.8 months. all patients had diarrhea lasting 14 or more days. bacterial overgrowth of the colonic microflora in the jejunal secretion, at concentrations above 10(4) colonies/ml, was present in 11 (68.7%) patients. the stool culture was positive for an enteropathogenic agent in 8 (50.0%) patients: for epec o111 in 2, epec o119 in ... | 2000 | 11105095 |
| the virulence plasmid pwr100 and the repertoire of proteins secreted by the type iii secretion apparatus of shigella flexneri. | bacteria of shigella spp. are the causative agents of shigellosis. the virulence traits of these pathogens include their ability to enter into epithelial cells and induce apoptosis in macrophages. expression of these functions requires the mxi-spa type iii secretion apparatus and the secreted ipaa-d proteins, all of which are encoded by a virulence plasmid. in wild-type strains, the activity of the secretion apparatus is tightly regulated and induced upon contact of bacteria with epithelial cell ... | 2000 | 11115111 |
| further studies on the gs element. a novel mycobacterial insertion sequence (is1612), inserted into an acetylase gene (mpa) in mycobacterium avium subsp. silvaticum but not in mycobacterium avium subsp. paratuberculosis. | we have recently described the gs element, found in mycobacterium avium subsp. paratuberculosis (map), mycobacterium avium subsp. silvaticum (mas) and some isolates of mycobacterium avium subsp. avium serotype 2 (maas2), which contains a set of genes of low gc% content, putatively associated with the biosynthesis, modification and transference of fucose to cell wall glycopeptidolipids. here we describe a further gene of low gc% content (mpa), within the gs element in map. mpa is a putative acety ... | 2000 | 11118730 |
| shigella flexneri luxs quorum-sensing system modulates virb expression but is not essential for virulence. | quorum-sensing systems regulate the expression of virulence factors in a wide variety of plant and animal pathogens, including members of the enterobacteriaceae. studies of shigella virulence gene expression have demonstrated that maximal expression of genes encoding the type iii secretion system and its substrates and maximal activity of this virulence organelle occur at high cell density. in these studies, we demonstrate that the expression of ipa, mxi, and spa invasion operons is maximal in s ... | 2001 | 11119484 |
| identification of functional regions within invasion plasmid antigen c (ipac) of shigella flexneri. | shigella flexneri causes bacillary dysentery with symptoms resulting from the inflammation that accompanies bacterial entry into the cells of the colonic epithelium. the effectors of s. flexneri invasion are the ipa proteins, particularly ipab and ipac, which are secreted at the host-pathogen interface following bacterial contact with a host cell. of the purified ipa proteins, only ipac has been shown to possess quantifiable in vitro activities that are related to cellular invasion. in this stud ... | 2001 | 11123692 |
| inactivation of gram-negative bacteria by lysozyme, denatured lysozyme, and lysozyme-derived peptides under high hydrostatic pressure. | we have studied the inactivation of six gram-negative bacteria (escherichia coli, pseudomonas fluorescens, salmonella enterica serovar typhimurium, salmonella enteritidis, shigella sonnei, and shigella flexneri) by high hydrostatic pressure treatment in the presence of hen egg-white lysozyme, partially or completely denatured lysozyme, or a synthetic cationic peptide derived from either hen egg white or coliphage t4 lysozyme. none of these compounds had a bactericidal or bacteriostatic effect on ... | 2001 | 11133464 |
| conserved regulatory elements of the promoter sequence of the gene rpoh of enteric bacteria. | the rpoh regulatory region of different members of the enteric bacteria family was sequenced or downloaded from genbank and compared. in addition, the transcriptional start sites of rpoh of yersinia frederiksenii and proteus mirabilis, two distant members of this family, were determined. sequences similar to the sigma(70) promoters p1, p4 and p5, to the sigma(e) promoter p3 and to boxes dnaa1, dnaa2, camp receptor protein (crp) boxes crp1, crp2 and box cytr present in escherichia coli k12, were ... | 2001 | 11139607 |
| production and characterization of a new monoclonal antibody against neisseria meningitidis: study of the cross-reactivity with different bacterial genera. | we have generated a hybridoma cell line which produces an 8c7br1 clone of the igm antibody isotype. it recognizes the 50-, 65-, and 60-kda antigens and is reactive with strains of n. meningitidis in the 98% of local neisseria genera by dot-elisa assays. two percent of the strains of n. meningitidis b do not present reactivity with the 8c7br1 monoclonal antibody (mab). the antibody reacted against n. meningitidis of serogroups a, b, c, x, y, z, and different serotypes and subtypes of n. meningiti ... | 2000 | 11152396 |
| structure-function analysis of the shigella virulence factor ipab. | infection by the gram-negative bacterium shigella flexneri results in dysentery, an acute inflammatory disease of the colon. essential events in the pathogenesis of shigella infections include bacterial invasion of epithelial cells, escape from the phagosome, and induction of apoptosis in macrophages. the shigella virulence factor invasion plasmid antigen b (ipab) is required for all of these processes. induction of apoptosis is dependent on ipab binding to the cysteine protease caspase-1 (casp- ... | 2001 | 11157939 |
| clonal relationships among shigella serotypes suggested by cryptic flagellin gene polymorphism. | the presence of cryptic flic alleles in the genomes of 120 strains representative of the four shigella species was investigated. one fragment was obtained by pcr amplification of flic, with a size varying from 1.2 to 3.2 kbp, depending on the species or serotype. after digestion with endonuclease hhai, the number of fragments in patterns varied from three to nine, with sizes of between 115 and 1,020 bp. patterns sharing most of their bands were grouped to constitute an f type. a total of 17 diff ... | 2001 | 11158126 |
| parameters underlying successful protection with live attenuated mutants in experimental shigellosis. | because the use of live attenuated mutants of shigella spp. represents a promising approach to protection against bacillary dysentery (m. e. etherridge, a. t. m. shamsul hoque, and d. a. sack, lab. anim. sci. 46:61-66, 1996), it becomes essential to rationalize this approach in animal models in order to optimize attenuation of virulence in the vaccine candidates, as well as their route and mode of administration, and to define the correlates of protection. in this study, we have compared three s ... | 2001 | 11160004 |
| genetic organization of the she pathogenicity island in shigella flexneri 2a. | in this study we report the complete nucleotide sequence and genetic organization of the she pathogenicity island (pai) of shigella flexneri 2a strain ysh6000t. the 46 603 bp she pai is situated adjacent to the 3' terminus of the phev trna gene and includes an imperfect direct repeat of the 3'-terminal 22 bp of the phev gene at the right boundary of the pai. the she pai carries a bacteriophage p4-like integrase gene within the phev -proximal boundary of the pai, intact and truncated mobile genet ... | 2001 | 11162180 |
| structure and composition of the shigella flexneri "needle complex", a part of its type iii secreton. | type iii secretion systems (ttsss or secretons), essential virulence determinants of many gram-negative bacteria, serve to translocate proteins directly from the bacteria into the host cytoplasm. electron microscopy (em) indicates that the ttsss of shigella flexneri are composed of: (1) an external needle; (2) a transmembrane domain; and (3) a cytoplasmic bulb. em analysis of purified and negatively stained parts 1, 2 and a portion of 3 of the ttss, together termed the "needle complex" (nc), pro ... | 2001 | 11169106 |
| secretion of predicted inc proteins of chlamydia pneumoniae by a heterologous type iii machinery. | chlamydia spp. are strictly intracellular pathogens that grow inside a vacuole, called an inclusion. they possess genes encoding proteins homologous to components of type iii secretion machineries, which, in other bacterial pathogens, are involved in delivery of bacterial proteins within or through the membrane of eukaryotic host cells. inc proteins are chlamydial proteins that are associated with the inclusion membrane and are characterized by the presence of a large hydrophobic domain in their ... | 2001 | 11169118 |
| microbes and microbial toxins: paradigms for microbial-mucosal interactions iii. shigellosis: from symptoms to molecular pathogenesis. | interaction of shigella flexneri with epithelial cells includes contact of bacteria with the cell surface and release of ipa proteins through a specialized type iii secreton. a complex signaling process involving activation of small gtpases of the rho family and c-src causes major rearrangements of the subcortical cytoskeleton, thereby allowing bacterial entry by macropinocytosis. after entry, shigellae escape to the cell cytoplasm and initiate intracytoplasmic movement through polar nucleation ... | 2001 | 11171613 |
| shigellae control the gates of ll. | 2001 | 11175842 | |
| downregulation of bactericidal peptides in enteric infections: a novel immune escape mechanism with bacterial dna as a potential regulator. | antibacterial peptides are active defense components of innate immunity. several studies confirm their importance at epithelial surfaces as immediate barrier effectors in preventing infection. here we report that early in shigella spp. infections, expression of the antibacterial peptides ll-37 and human beta-defensin-1 is reduced or turned off. the downregulation is detected in biopsies from patients with bacillary dysenteries and in shigella- infected cell cultures of epithelial and monocyte or ... | 2001 | 11175848 |
| a new target for shigellosis: rational design and crystallographic studies of inhibitors of trna-guanine transglycosylase. | eubacterial trna-guanine transglycosylase (tgt) is involved in the hyper-modification of cognate trnas leading to the exchange of g34 at the wobble position in the anticodon loop by preq1 (2-amino-5-(aminomethyl)pyrrolo[2,3-d]pyrimidin-4(3h)-one) as part of the biosynthesis of queuine (q). mutation of the tgt gene in shigella flexneri results in a significant loss of pathogenicity of the bacterium, revealing tgt as a new target for the design of potent drugs against shigellosis. the x-ray struct ... | 2001 | 11178905 |
| safety and immunogenicity of improved shigella o-specific polysaccharide-protein conjugate vaccines in adults in israel. | data suggest that the o-specific polysaccharide (o-sp) domain of the lipopolysaccharide (lps) of shigella species is both an essential virulence factor and a protective antigen and that a critical level of serum immunoglobulin g (igg) to this antigen will confer immunity to shigellosis. because covalent attachment of polysaccharides to proteins increases their immunogenicity, especially in infants and in young children, the o-sp of shigella species were bound to medically useful proteins, and th ... | 2001 | 11179298 |
| identification and characterization of an in vivo regulated d15/oma87 homologue in shigella flexneri using differential display polymerase chain reaction. | shigella genes expressed during infection likely contribute to adaptation and virulence in the host. using differential display pcr (ddpcr), a cdna fragment from shigella flexneri serotype 5 that showed enhanced expression in a murine model was identified, cloned and sequenced. enhanced expression was verified by rna dot blot. the full-length gene was cloned using pcr and sequenced. the complete gene sequence was blast searched against genbank, and exhibited strong homology to genes encoding hae ... | 2001 | 11179681 |
| inhibition of shigella flexneri-induced transepithelial migration of polymorphonuclear leucocytes by cadaverine. | dysentery caused by shigella species is characterized by infiltration of polymorphonuclear leucocytes (pmns) into the colonic mucosa. shigella spp. evolved into pathogens by the acquisition of virulence genes and by the deletion of 'antivirulence' genes detrimental to its pathogenic lifestyle. an example is cada (encoding lysine decarboxylase), which is uniformly absent in shigella spp., whereas it is present in nearly all isolates of the closely related non-pathogen escherichia coli. here, usin ... | 1999 | 11207548 |
| the secreted ipab and ipac invasins and their cytoplasmic chaperone ipgc are required for intercellular dissemination of shigella flexneri. | invasion of epithelial cells by shigella flexneri involves entry and dissemination. the main effectors of entry, ipab and ipac, are also required for contact haemolytic activity and escape from the phagosome in infected macrophages. these proteins are stored in the cytoplasm in association with the chaperone ipgc, before their secretion by a type iii secretion apparatus is activated by host cells. we used a his-tagged ipgc protein to purify ipgc-containing complexes and showed that only ipab and ... | 1999 | 11207551 |
| cd44 binds to the shigella ipab protein and participates in bacterial invasion of epithelial cells. | shigella entry into epithelial cells is characterized by a transient reorganization of the host cell cytoskeleton at the site of bacterial interaction with the cell membrane, which leads to bacterial engulfment in a macropinocytic process. using affinity chromatography on hela cell extracts, we show here that the hyaluronan receptor cd44 associates with ipab, a shigella protein that is secreted upon cell contact. overlay and solid-phase assays indicated that ipab binds directly to the extracellu ... | 2000 | 11207560 |
| pathogen-induced apoptosis of macrophages: a common end for different pathogenic strategies. | microbe-macrophage interactions play a central role in the pathogenesis of many infections. several bacterial pathogens induce apoptosis specifically in macrophages, but the mechanisms by which it occurs differ, and the resulting pathology can take different courses. macrophage death caused by shigella flexneri and salmonella spp. has been shown to result in the release of pro-inflammatory cytokines. conversely, yersinia spp. induce apoptosis by suppressing the signalling pathways that lead to t ... | 2000 | 11207583 |
| the regulatory protein phop controls susceptibility to the host inflammatory response in shigella flexneri. | the phop/phoq two-component regulatory system controls transcription of several key virulence genes essential for salmonella survival in the host cell phagosome. here, we determine that the phop/phoq system also regulates virulence in the aetiological agent of bacillary dysentery, shigella flexneri, even though this pathogen escapes from the phagosome into the cytoplasm of the host cell. a phop mutant of shigella established infections and induced an acute inflammatory response in two different ... | 2000 | 11207599 |
| functional role for the class ix myosin myr5 in epithelial cell infection by shigella flexneri. | efficient control of shigella-induced, rho-dependent cytoskeletal rearrangements seems to be required to shape the delicate cellular structures associated with bacterial invasion of epithelial cells. we therefore studied a class ix myosin and rho antagonist, the gtpase-activating protein (gap) myr5, for a potential role in the bacterial entry process. we show that myr5 is recruited into bacterial entry spots. the recruitment pattern resembled that of rhoc or ezrin, but not rhoa, rac or cdc42, wh ... | 2000 | 11207612 |
| periplasmic transit and disulfide bond formation of the autotransported shigella protein icsa. | the shigella outer membrane protein icsa belongs to the family of type v secreted (autotransported) virulence factors. members of this family mediate their own translocation across the bacterial outer membrane: the carboxy-terminal beta domain forms a beta barrel channel in the outer membrane through which the amino-terminal alpha domain passes. icsa, which is localized at one pole of the bacterium, mediates actin assembly by shigella, which is essential for bacterial intracellular movement and ... | 2001 | 11208794 |
| [diagnostic value of a novel nutrient medium for isolation and cultivation of pathogens causing enteric yersiniosis and pseudotuberculosis]. | a new nutrient medium for isolation and cultivation of the causative agents of enteric yersiniosis and pseudotuberculosis was found to have advantages over endo medium in its differentiating and inhibiting properties. this medium permitted the easy differentiation of yersinia pseudotuberculosis from y. enterocolitica, as well as from escherichia coli, shigella flexneri, klebsiella pneumoniae, k. rhinoscleromatis, hafnia, enterobacter and citrobacter by color; from proteus inconstans by swarming. ... | 2000 | 11210625 |
| [bactericidal properties of hemo-cytolysin from vibrio cholerae non o1 p-11702 strain in a panel of indicator cultures for detection of vibriocins]. | the influence of the preparation of hemo-cytolysin, obtained from v. cholerae non o1 strain p-11702 and inducing lysis of both red blood cells and v. cholerae cultures using a panel of indicator cultures for the detection of vibriocins, was studied. the set of indicator cultures contained 2 shigella flexneri strains, 1 s. dysenteriae strain, 3 s. sonnei strains, 3 escherichia coli strains and 2 v. cholerae strains, one of them being atypical. hemo-cytolysin exhibited lytic activity with respect ... | 2000 | 11210647 |
| molecular characterization of global regulatory rna species that control pathogenicity factors in erwinia amylovora and erwinia herbicola pv. gypsophilae. | rsmb(ecc) specifies a nontranslatable rna regulator that controls exoprotein production and pathogenicity in soft rot-causing erwinia carotovora subsp. carotovora. this effect of rsmb(ecc) rna is mediated mostly by neutralizing the function of rsma(ecc), an rna-binding protein of e. carotovora subsp. carotovora, which acts as a global negative regulator. to determine the occurrence of functional homologs of rsmb(ecc) in non-soft-rot-causing erwinia species, we cloned the rsmb genes of e. amylovo ... | 2001 | 11222584 |
| molecular epidemiology of a shigella flexneri outbreak in a mountainous township in taiwan, republic of china. | an outbreak of shigellosis occurred in a township of nantou conuty in central taiwan from august to october in 1996. the infections extended to two neighboring townships and continued to the end of 1996. forty cases were confirmed during the period, in contrast to only one confirmed case in nantou county in 1996 before the outbreak. all of these 41 cases in 1996 were identified as infections with shigella flexneri serotype 2a. in order to trace the source of the infections, the 41 isolates recov ... | 2001 | 11230426 |
| increased nitrite and nitrate concentrations in sera and urine of patients with cholera or shigellosis. | nitric oxide (no) is an important regulator of cell function. in the intestine, no regulates blood flow, peristalsis, secretion, and is associated with inflammation and tissue injury. the objectives of this study were to assess and compare the role of no in cholera, a noninflammatory enteric infection, and in shigellosis, a bacterial inflammation of the colon. | 2001 | 11232692 |
| bovine milk antibodies for health. | the immunoglobulins of bovine colostrum provide the major antimicrobial protection against microbial infections and confer a passive immunity to the newborn calf until its own immune system matures. the concentration in colostrum of specific antibodies against pathogens can be raised by immunising cows with these pathogens or their antigens. immune milk products are preparations made of such hyperimmune colostrum or antibodies enriched from it. these preparations can be used to give effective sp ... | 2000 | 11242458 |
| regulating cellular actin assembly. | cellular actin assembly is tightly regulated. the study of pathogen motility has led to the identification of several cellular factors that are critical for controlling this process. pathogens such as listeria require ena/vasp and arp2/3 proteins to translate actin polymerization into movement. recent work has extended these observations and uncovered some similarities and surprising differences in the way cells and pathogens utilize the actin cytoskeleton. | 2001 | 11248549 |
| spa33, a cell surface-associated subunit of the mxi-spa type iii secretory pathway of shigella flexneri, regulates ipa protein traffic. | the mxi-spa type iii secretion system of shigella flexneri directs the host cell contact-induced secretion of a set of invasins, referred to as ipas. in this study, we examined the role of spa33 in ipa secretion. a spa33-null mutant was both noninvasive and unable to translocate the ipas from inner membrane to outer membrane (om) positions of the mxi-spa transmembrane channel. spa33 was found to be a mxi-spa substrate that is translocated to the bacterial cell surface upon the induction of ipa s ... | 2001 | 11254573 |
| synthesis of mannich bases of some 2,5-disubstituted 4-thiazolidinones and evaluation of their antimicrobial activities. | 5-phenyl/methyl-5-morpholinomethyl/pyrrolidinomethyl-2-(5- aryl-1,3,4-oxadiazol-2-yl)imino]-4-thiazolidinones (5a-m) were synthesized by the reaction of 5-phenyl/methyl-2-[(5-aryl-1,3,4-oxadiazol -2-yl)imino]-4-thiazolidinones (4a-j) with formaldehyde and morpholine or pyrrolidine. the structures of the compounds were determined by analytical and spectral (ir, 1h-nmr, eims) methods. the antibacterial activities of the novel compounds against staphylococcus aureus atcc 6538, staphylococcus epider ... | 2001 | 11268772 |
| type iv o antigen modification genes in the genome of shigella flexneri nctc 8296. | the genes encoding type iv o antigen glucosylation were characterized from both escherichia coli and shigella flexneri. the putative o antigen modification genes from e. coli, o120 o306 o443, were pcr-amplified and introduced into s. flexneri serotype y strain sfl124. immunogold labelling and phage sensitivity indicated the presence of both serotype y and serotype 4a o antigens on the cell surface of the resulting recombinant sfl124 strains, suggesting that only partial serotype conversion was c ... | 2001 | 11283281 |
| influence of infection of cells with bacteria associated with reactive arthritis on the peptide repertoire presented by hla-b27. | reactive arthritis (rea) after infections with various gram-negative bacteria is strongly associated with the mhc class i molecule hla-b27. it is supposed that the b27 molecule itself plays a role in the pathogenesis of rea by presenting antigenic peptides to cytotoxic t lymphocytes. the peptide repertoires presented by salmonella-, shigella- and non-infected cells were compared to identify such peptides. from the peptides isolated from the b27 molecules of these cells, profiles were generated b ... | 2001 | 11289525 |
| attenuated shigella flexneri 2a delta guaba strain cvd 1204 expressing enterotoxigenic escherichia coli (etec) cs2 and cs3 fimbriae as a live mucosal vaccine against shigella and etec infection. | to construct a prototype hybrid vaccine against shigella and enterotoxigenic escherichia coli (etec), the genes encoding the production of etec cs2 and cs3 fimbriae were isolated and expressed in attenuated shigella flexneri 2a guaba strain cvd 1204. the cs2 cota to -d genes, isolated from etec strain c91f, and the cs3 csta to -h genes, subcloned from plasmid pcs100, were cloned into ~15-copy-number-stabilized pga1 behind the osmotically regulated ompc promoter, resulting in high expression of b ... | 2001 | 11292735 |